This is a filler story that falls between books 4 and 5 of The Sookie Stackhouse Novels. While it's not necessary to read it; it does help fill in the storyline a little bit. 

As with all of these stories, I find myself comparing them to the TV Series as I watched it first and I don't really recall the Fairy characters (though it's been long time since I've watched it - a rerun might be necessary). 

If you just can't get enough of Sookie Stackhouse and her extraordinary life, then I recommend you check this out!